1. Field of the Invention
This invention relates to a method of reading and writing a magnetic recording medium.
2. Description of the Related Art
In order to raise the recording density of a hard disk drive (HDD), in addition to improving the magnetic recording layer, the distance between the magnetic head which performs information reading and writing and the magnetic recording layer (the magnetic spacing) must be made as small as possible. To this end, the protective film formed on the magnetic recording layer is made thinner, the lubricating film formed on the protective film is made thinner, and the flying height of the magnetic head from the lubricating film surface is reduced. In recent HDDs, rather than reducing the flying height of the magnetic head from the lubricating film surface, magnetic heads are being used in which a technique is applied to bring only the element portion of the magnetic head close to the medium by means of thermal expansion, to lower the effective flying height (the distance from the protective film surface to the element portion of the magnetic head). This technique has been called the dynamic flying height (DFH) technique, thermal flying height control (TFC) technique, flying on demand (FOD) technique, and similar (see for example Japanese Patent Application Laid-open No. 2003-168274).
However, at present the protective film thickness, lubricating film thickness, and effective flying height are each several nm or less in magnitude, and further reduction of the thickness of the protective film may result in poorer corrosion resistance, while a thinner lubricating film may cause worsened durability, and reducing the effective flying height may lead to instability in head flight characteristics.
Hence an object of the present invention is to provide a method of reading and writing a magnetic recording medium to achieve further reduction of the magnetic spacing and improved electromagnetic transducing characteristics, without impairing head-disk interface (HDI) reliability as represented by corrosion resistance, durability, and head flight characteristics.